title: Intracellular alkalosis induced by increasing extracellular potassium. Ionic dependence and effects of amiloride and DIDS.
abstract: The intracellular alkalinization produced when extracellular potassium concentration is increased above its normal levels was studied in the rat diaphragm muscle by determination of the steady-state distribution of [14C]-5,5-dimethyl-2,4-oxazolidinedione (DMO). Replacement of external Na+ with sucrose and Mg2+ or N-methyl-D-glucamine prevented the rise in intracellular pH. Amiloride (1 mM) also abolished the elevation of intracellular pH, while the removal of external Cl- (replaced by gluconate) or addition of 0.1 mM 4-acetamido-4'-diisothyocyanostilbene-2,2-disulfonic acid (DIDS) did not prevent intracellular alkalinization from taking place. These results suggest that in the rat diaphragm muscle a Na(+)-dependent, amiloride-sensitive transport mechanism, perhaps Na+/H+ exchange, plays a major role in the K(+)-induced intracellular alkalinization. This mechanism might account for the metabolic acidosis produced by hyperkalemia.
authors.affiliation: Instituto de Investigaciones Cardiológicas, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
authors.forename: G A
authors.initials: GA
authors.lastname: Altenberg
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D000471:Alkalosis / Q000139:chemically induced*; D000584:Amiloride / Q000494:pharmacology*; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D003964:Diaphragm / Q000187:drug effects* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000633:toxicity*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000494:pharmacology
chemical_list: D002712:Chlorides; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D000584:Amiloride; D012964:Sodium; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D011188:Potassium